Finance Receivables - Aging Analysis (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	$ 93,275	$ 106,375
Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	73,545	78,170
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	868	845
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,676	2,599
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,692	6,790
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	12,875	13,939
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	22,967	21,074
Financing Receivable, Year One, Originated, Current Fiscal Year	27,467	32,923
Non-Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	19,730	28,205
Financing Receivable, Revolving	16,944	24,996
Non-Consumer Segment [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	410	552
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	75	149
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	182	124
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	47	242
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	114	78
Financing Receivable, Year One, Originated, Current Fiscal Year	425	376
Non-Consumer Segment [Member] | Group I [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	14,779	20,017
Financing Receivable, Revolving	13,670	18,769
Non-Consumer Segment [Member] | Group I [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	391	503
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	68	129
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	151	110
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	45	188
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	109	70
Financing Receivable, Year One, Originated, Current Fiscal Year	345	248
Non-Consumer Segment [Member] | Group II [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	2,793	4,874
Financing Receivable, Revolving	2,689	4,680
Non-Consumer Segment [Member] | Group II [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11	38
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7	20
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	26	11
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2	35
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	4	3
Financing Receivable, Year One, Originated, Current Fiscal Year	54	87
Non-Consumer Segment [Member] | Group III [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	559	1,533
Financing Receivable, Revolving	529	1,464
Non-Consumer Segment [Member] | Group III [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	8	9
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1	3
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	19
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1	3
Financing Receivable, Year One, Originated, Current Fiscal Year	20	35
Non-Consumer Segment [Member] | Group IV [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	66	93
Financing Receivable, Revolving	56	83
Non-Consumer Segment [Member] | Group IV [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	2
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	2
Financing Receivable, Year One, Originated, Current Fiscal Year	6	6
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	72,789	77,285
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	812	782
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,608	2,519
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,568	6,656
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	12,717	13,725
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	22,730	20,856
Financing Receivable, Year One, Originated, Current Fiscal Year	27,354	32,747
31-60 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	586	681
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	39	45
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	52	62
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	98	103
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	120	162
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	186	166
Financing Receivable, Year One, Originated, Current Fiscal Year	91	143
Financing Receivables, 61-120 Days past due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	127	163
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7	7
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10	12
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	20	24
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	29	44
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	40	45
Financing Receivable, Year One, Originated, Current Fiscal Year	21	31
Greater Than 120 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	43	41
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	10	11
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6	6
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6	7
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	9	8
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	11	7
Financing Receivable, Year One, Originated, Current Fiscal Year	1	2
Total past due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	756	885
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	56	63
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	68	80
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	124	134
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	158	214
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	237	218
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 113	$ 176